Question

I need to load lots of big images (500 .png files) from the SD card to my app. Do I always have to convert images to Bitmap and make Bitmap files? I don t want to resize the Heap. Is there another way to read the images from SD card?

Answer 1

If you re displaying them in a view, then you have to load them into memory in their entirety.

你没有提及你的形象将如何大,但我们在光彩中所做的事情是保留一份<代码>清单。 SoftReferences to these bitmaps, so that the garbage Collectionor can ob them when they re notprofile (i.e. when the view showing them have discarded-make ensure that this actual when, e.g. by using AdapterView/code>). 用这些比照图的齐装来判断这一点,你应该好。

Answer 2

在座标中,图像的内部表述是分光和斜体,而不是任何特定格式(png、bmp等)的形象。

当图象由BitmapFactory装上时,图像被转换为内部代表。

装上所有轨道图通常不是一个好的想法,你很快将摆脱记忆......

Answer 3

如果你的形象面貌非常大,那么,在装上图像前,你必须加以改变。否则,即使有一幅照片,也很容易造成记忆问题。我不知道你们想要同时展示多少形象,以及这些形象的大小。但是,我建议你在显示这些想法之前重新加以利用。

为了改变形象和显示形象,你可以使用这一守则:

    BitmapFactory.Options bitmapOptions = new BitmapFactory.Options();
    bitmapOptions.inJustDecodeBounds = true;
    BitmapFactory.decodeStream(fileInputStream, null, bitmapOptions);

    //reduce the image size
    int imageWidth = bitmapOptions.outWidth;
    int imageHeight = bitmapOptions.outHeight;
    int scale = 1;
    while (imageWidth/scale >= screenWidth && imageHeight/scale >= screenHeight) {
        imageWidth = imageWidth / 2;
        imageHeight = imageHeight / 2;
        scale = scale * 2;
    }

    //decode the image with necessary size
    fileInputStream = new FileInputStream(cacheFile);
    bitmapOptions.inSampleSize = scale;
    bitmapOptions.inJustDecodeBounds = false;
    imageBitmap = BitmapFactory.decodeStream(fileInputStream, null, bitmapOptions);
    ImageView imageView = (ImageView)this.findViewById(R.id.preview);
    imageView.setImageBitmap(imageBitmap);

在我的波塔项目中,我正在利用这部法典,将我的克民共体的挂图转作审查。

Android Save And Loaddownload Locally

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